Rap1 is a close relative of the small GTPase Ras, and was identified in a screen for revertants of cells oncogenically transformed by mutant Ras. Rap1 is activated — that is increased GTP-bound over ...

After engagement of the T cell receptor (TCR) by antigen-presenting cells, multiple T cell signaling systems come into play. The simultaneous deployment of several signaling cascades is thought to ...